I have been saved from disaster twice.
I used to use Norton Ghost to make a complete image of my home PC's HDD (data, programs, operating system, partitions, boot sector and all) at least monthly to an extra HDD in the same machine. If anything went wrong it was a simple matter of restoring the image to the main drive using a boot disk.
I still use the same system but with the following additions:
Instead of Norton Ghost I now use Acronis true image, for many reasons but mainly; price, external USB HDD support and task scheduling.
Incremental backups are now done every Monday morning while I'm away from the machine.
And once a month I copy the image to an external USB drive which is kept off site (at work).
If you have a spare drive I highly recommend you download the Acronis Trial and give it a go free for 30 days (15 days?).
If you decide to purchase it from the web site by download, use the coupon code CHRISTMAS in the online order form to get it for $40 AUD instead of ~$80. http://www.acronis.com/homecomputing...cts/trueimage/
You can also back up individual files from the image if only a couple get corrupted / get accidentally deleted.